The proteoglycans are important constituents of the dermis, as of most connective tissues. In this tissue they are closely related to collagen and are probably involved in its structural organization. Few studies have been directed at the isolation and structure of skin proteoglycans, especially dermatansulfate-protein. Methods will be sought for the extraction and purification of proteoglycans from dermis. The chemical nature and physical interactions of the products will be studied, especially with regard to binding to hyaluronic acid (by analogy with the molecular phenomena found in cartilage). Antibodies to skin proteoglycans will be prepared, and their immunological relationships will be compared to those of cartilage. Changes in the quantity and relationships of the proteoglycans will be correlated with aging or physiological state.